Maybe Harris doesn't know that there is now a fake differential brake that enables itself when you switch off the DSC? I suspect that is why he didn't have his expected traction problems.

I can not tell 100% for sure..
But when he is talking about LSDs from about 15 minutes into the reviews. He says he find it hard to criticize BMWs open diff AND THE ELECTRONICS.
So he probably knows. Chris is not the guy do drive on a track with DSC, DTC and that stuff.
He can can usually feel the difference between a Torsen LSD, and a Clutch type LSD. So I don't doubt he figured out that the car had some form of E-diff if he was not aware. Most likely he knew about it before the review..

38mpg from an n55 ? How come I get 20mpg for the us spec n55? Is it cause theres something to do with the quality of our gas?

Two reasons:
The biggest one is that the 1 US gallon equals roughly 1.2 UK gallons. And the other is that M135i has 8 gears where yours has 6 or 7 depending on your transmission. I suppose gas quality could be a factor too, but it would not be a significant as the other two.

38mpg from an n55 ? How come I get 20mpg for the us spec n55? Is it cause theres something to do with the quality of our gas?

Two reasons:
The biggest one is that the 1 US gallon equals roughly 1.2 UK gallons. And the other is that M135i has 8 gears where yours has 6 or 7 depending on your transmission. I suppose gas quality could be a factor too, but it would not be a significant as the other two.

If 1 us gallon = 1.2 uk gallons, the us MPG figure should be higher, right?

what a fantastic review, finally. Gotta love Chris harris. He test the cars exactly how it is supposed to be done, adresseing the right questions, gives a very detailed and understandable feedback about the feel of the car etc Obsiouly knows what he's talking about.

The engine-noise of that M135 gives me goose bumps, lovely!

Chris states "it is the bargain of the year". I would go even further, gotta be the bargain of decades

If I could wish for just one more thing I would have liked to see him drifting the car, just to see how the electronic diff keep up in that aspect.

He does mention it is "not as natural driftcar as 1M" because of the missing limited slip diff but he is impressed with the electronic diff. Would have liked to see how much "worse" it is at drifting.

sure the looks aren't the best but in every other aspect the M135i is such a winner.